Performance of an on-site urine multidrug test used by forensic physicians in determining the cause of death

Forensic physicians in the region of Amsterdam routinely collect blood and urine samples during external examinations. A rapid on-site multidrug test is used to screen the urine samples for the presence of commonly used drugs classes. Urine and blood samples are sent to the laboratory for additional toxicological analysis. This study aimed to investigate how the substances found in urine using the on-site multidrug test relate to the substances identified with laboratory methods. In 2018 and 2019, 465 cases underwent an on-site multidrug test as well as toxicological laboratory analyses and were included in this study. Fifty-three percent (n = 247) of these cases included a positive on-site multidrug test for at least one substance. The level of total agreement between the on-site multidrug test performed by the forensic physician and the laboratory analyses either in urine or in blood varied per substance groups, with the best results for barbiturates, cocaine, ecstasy and methadone. In conclusion, the on-site multidrug test appeared to perform well for certain substance groups and is an economical and rapid tool. However, the results from the laboratory analyses in blood occasionally provided additional insights concerning the circumstances that could be of importance in the cause of death.